Flywheel systems for power storage include a rotor that stores energy when rotated, a motor/generator (“MG”) that converts energy between electrical and mechanical forms, and a bearing system that supports the rotating components. However, current flywheel-based energy storage devices are unable to provide power continuously for greater than fifteen minutes and are still too expensive for wide acceptance. For instance, the best conventional system available from the flywheel industry provides power for approximately two minutes, and the best available solution on grid runs for approximately fifteen minutes. Accordingly, an improved system design having a lower cost and higher reliability may be beneficial. Also, reducing the mass and volume and increasing the power density over conventional systems may be beneficial.